The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 1987
Filed:
Dec. 29, 1986
Isao Hattori, Nagoya, JP;
Shigeru Furukawa, Nagoya, JP;
NGK Insulators, Ltd., , JP;
Abstract
An evacuating device for a plunger molding apparatus including a material cylinder for receiving a blank to be extruded, a ram head slidably engageable in the material cylinder, a hydraulic plunger having a piston connected to the ram head, an evacuating cap provided slidably in an air-tight manner on the piston and having evacuating pipes, and a blowdown valve provided in the ram head for closing and opening an air blow aperture formed in the ram head. The ram head has a flat surface which is in contact with the blank in the material cylinder. An O-ring is arranged in the flat surface of the ram head about the air blow aperture. The blowdown valve consists of a stem and a head which is brought into contact with the flat surface of the ram head through the O-ring when the ram head is being advanced, thereby improving the air-tightness between the ram head and the blowdown valve to prevent the ceramic batch from entering the air blow aperture. Upon retraction of the ram head, therefore, the air blowing through the blowdown valve can be beneficially effected with ease.